Difference Between “Say” and “Tell” (mostly asked question)

Q:What’s the Difference Between “Say” and “Tell”? 

Ans:  

We only use 'tell' to mean instruct or inform. 'I told him to wait for me on the platform'... that's an instruction. "My father used to tell me wonderful stories" - informing me.

We use 'tell' without a personal object in a few expressions, that are kind of fixed expressions like tell the truth, tell the time and tell the difference.

'Say' can be used for any kind of talking. So here are three sentences where you could not use 'tell':

She said 'Where have you been?'

So I said what a good idea.

Shoaib said 'What's the matter?'

we use 'say' before words like a word, a name, or a sentence. An example would be: 'Don't say a word.

I hope this answer will help u to clear your concepts.